12 n 
Fig. 6 Cross-sectional areas of tumors in the 4 
experimental groups: (1) ADV/bgal and PBS 
(TK-G-) ; (2) ADV/bgal plus GCV (TK-G+); (3) 
ADV-tk plus PBS (TK+G-); and (4) ADV-tk plus 
GCV (TK+G+). The maximal cross-sectional 
areas of the tumors were measured by 
computerized morphometric analysis. The 
mean cross-sectional area of the treated group 
was 0.381 ± 0.48 mm 2 (n=4) compared to 
7.195 ± 0.88 mm 2 (n=5) for the TK-G+ group, 
9.584 ± 1 .24 mm 2 (n=5) for the TK+G- group, 
and 9.268 ± 1 .00 mm 2 (n=5) for the TK-G- 
group. 
E 
E 
03 
CD 
O 
E 
=3 
E— 
E 
X 
CO 
Fig. 7 Photomicrographs of coronal sections of brains from animals that had received 9L 
tumor cell injections and then were treated with A ADV-bgal and GCV or B ADV-tk and GCV 
(lOOmg/kg). An arrowhead marks the former tumor site. The animals were perfused with 
fixative 20 days after tumor cell injection. 
Recombinant DNA Research, Volume 20 
[735] 
